This invention is related to a method of inserting bristles into a brush and, more specifically, to a method for inserting bristles which are not oriented perpendicular to the surface of the brush.
The variety of brands, designs, and styles of toothbrushes available in the United States today is truly staggering. Brushes are available in sizes and styles appropriate for babies, adults, dentures, sensitive gums, and other specialized needs. As consumers become more concerned about oral hygiene, manufacturers have designed brushes whose bristles are optimized to reach and clean the irregular surfaces of the teeth. The bristles of these new brushes are in bundles of different sizes and shapes and are frequently oriented at an angle other than 90xc2x0 with respect to the face of the brush. While these brushes may be more effective at cleaning teeth, the various angles at which the bristles are inserted can make manufacturing difficult. In automated machinery, material is typically fed into an apparatus from a single supply at a singe orientation with respect to the apparatus. A mechanism is necessary which can vary the orientation of the material as it is fed into a machine.
In one aspect, the invention is a method for feeding bristle bundles into a magazine comprising the steps of passing bristle bundle material into a plurality of channels in the feedblock, passing the bristle bundle material from the channels in the feedblock into corresponding adjacent channels in a first transition plate, and passing the bristle bundle material from the channels in the first transition plate into a set of corresponding channels in the magazine. The channels in the feedblock are parallel to one another and at least a portion of the channels in the first transition plate are not parallel to the channels in the feedblock. The method may further comprise passing the bristle bundle material from the channels in the first transition plate into a set of corresponding channels in a second transition plate abutting the first transition plate. At least a portion of the channels in the second transition plate are not parallel to the corresponding channels in the first transition plate. The orientation of at least a portion of the channels in the second transition plate may be offset from an orientation of the channels in the feedblock by a first angle and from an orientation of the channels in the first transition plate by a second angle. The method may further comprise repeating the passing step with at least a subsequent transition plate. A portion of the channels in the magazine may be skewed with respect to one another or lie in intersecting planes. The orientation of a portion of the channels in the first transition plate and the orientation of the channels in the feedblock may be offset by an angle greater than 0xc2x0. The channels of the feedblock and the channels of the first transition plate may have a first and a second end, and the first end of each of the channels, from which the bristle bundle material passes to the second end, may have a chamfer to increase the diameter of a portion of the channel.
In another aspect, the invention is an apparatus for feeding bristle bundles into a magazine from a supply. The apparatus includes a feedblock, parallel channels in the feedblock for receiving bristle bundle material from a supply, a first transition plate abutting the feedblock, corresponding channels in the first transition plate to receive the bristle bundle material from the channels in the feedblock, and corresponding channels in the magazine which receive the bristle bundle material which has been passed through the first transition plate. At least a portion of the channels in the feedblock are not parallel to the corresponding channels in the first transition plate. The apparatus may further comprise an additional transition plate interposed between the feedblock and the magazine, wherein the bristle bundle material can be passed from the channels in the feedblock into the corresponding channels in the magazine via the channels in the transition plates. A portion of the channels in the additional transition plate are not parallel to the corresponding channels in the feedblock or the first transition plate. An orientation of at least a portion of the channels in the additional transition plate are offset from an orientation of the channels in the feedblock by a first angle and from an orientation of the channels in the second transition plate by a second angle. The apparatus may further comprise a plurality of additional transition plates. The channels of the feedblock and the channels of the first transition plate may each have a first and second end. The bristle bundle material passes from the first end of the channels to the second end, and the first end of each of the channels may have a chamfer to increase the diameter of a portion of the channel. The channels in the first transition plate may not all be parallel to one another, and an orientation of a portion of the channels in the first transition plate and an orientation of the corresponding channels in the feedblock may be offset by an angle greater than 0xc2x0. A portion of the channels in the magazine may be skewed with respect to one another or lie in intersecting planes.
BRIEF DESCRIPTION OF THE DRAWING The invention is described with reference to the several figures of the drawing, in which,
FIG. 1A is a side view of a bristle feeding apparatus and a magazine;
FIG. 1B is a front view of a portion of the magazine;
FIG. 2 is a top view of a toothbrush head;
FIGS. 3A and 3B are cross-sectional views cut from the side of a feedblock and a set of transition plates;
FIG. 3C is a cross-sectional view cut from the top of a feedblock and a set of transition plates; .
FIG. 3D is an exploded view of a chamber in a transition plate; and
FIGS. 4A-E are diagrams of a set of transition plates showing the angles of channels in the plates with respect to the plates.